The present invention relates to a transmission drive unit having an improved transmission of forces that can occur, in particular, in the case of an accident.
Transmission drive units are known in differing realizations from the prior art. For example, such drives are used in motor vehicles, for the purpose of adjusting movable devices, for example for seat adjustment. Such transmission drive units have at least one interface to the vehicle, two interfaces to the customer structure usually being required in the case of spindle motors. Differing interfaces are to be provided in this case, according to the vehicle. Further, differing installation situations arise, depending on the vehicle. The result of this is that it is necessary to provide a multiplicity of individual components on the transmission drive unit in order to be properly adapted to the respective application. This results in a multiplicity of designs, whereby the production costs of such drive units are increased. It would therefore be desirable to have a transmission drive unit that can be adapted as easily as possible to differing installation situations and that has as many shared components as possible. A further problem arises in the selection of the material of differing components of the transmission drive units. In principle, greater forces can be achieved through use of metal housings. For weight reasons, aluminum is normally used in this case. Nevertheless, since the required tolerances cannot be achieved with the methods of producing such a metal housing, a stock-removing machining of functional surfaces must be performed. Alternatively, it would be possible to provide transmission housings made of plastic, which, however, can transfer only lesser forces. Frequently, therefore, such plastic housings break in the case of an accident, which can result in persons being endangered, for example on a vehicle seat.